Gas detectors are generally known. Such devices may be fixed or portable and may be used in the home setting to detect natural gas leaks or in an industrial setting to detect natural gas or other hazardous gases.
In the industrial setting, hazardous gases may represent a threat on any of a number of different levels. On one level, the gas may be explosive above certain concentrations. Alternatively, the gas may be toxic above certain concentrations when inhaled by any person in the area. On still another level, the gas may be a product of combustion that is either toxic or that suggests an imminent threat of explosion or fire.
In order to ensure the overall safety of a facility, gas detectors are often required wherever people are present. Each of the detectors may include or be associated with local visual or audible alarms to alert a user and nearby persons to threats.
In many facilities, gas detectors (both fixed and portable) are distributed throughout the facility and connected to a central monitoring station. In the event that a threat is detected by one station, a general alarm may be sounded throughout the facility to evacuate the facility.
In other, larger facilities, it may not be possible to evacuate the entire facility. In these cases, the gas detectors may be segregated into zones based upon geographic location or risk. In these cases, the detection of a threat in any one area may only require the evacuation of the affected zone.
While such centralized systems work well, it is often difficult to coordinate evacuations of people away from the threat. A public address system may be needed, but such systems may not work or could become damaged. Accordingly, better methods are needed to coordinate evacuations in such situations.